Green Polymers and Their Uses in Petroleum Industry, Current State and Future Perspectives

The concept of green chemistry has been established to find safe methodologies and environmentally benign solutions for the present and the onset problems. In this regard, extensive work has been carried out worldwide to replace the currently used materials with green ones. The terminology green relies on all the non-pollutive or the degradable materials regardless of their source. Therefore, there are biobased green materials and non-biobased green materials. This review sheds light on several green polymers used in different petroleum industries. The polymers are reviewed according to the stage of oil processing in which they are applied. Furthermore, different modification methodologies of natural polymers are revised. Also, the role of green non-biopolymers in different petroleum industries is investigated. It is worth mentioning that we concentrate our efforts on the utilization of different natural polymers in petroleum applications. Thereafter, some natural polymers such as chitosan and cellulose and their derivatives were specifically reviewed

EFFECT OF SOME OF ORGANIC AND BIO AND/OR MINERAL FERTILIZATION ON VEGETATIVE GROWTH AND CHEMICAL COMPOSITION OF DELONIX REGIA

This work wasexecuted during two successive seasons of 2018 and 2019 in the nursery and laboratory of Fac. Agric., Minia Univ., Egypt to investigate the response of vegetative and root growthand some chemical composition of Delonix regia seedlings to four percentages of humic acid (0, 1, 2 and 4%) and four bio- and/or mineral NPK fertilization treatments (control, 100% NPK, Minia Azotein and 75% NPK plus Minia Azotein), as well as, the interaction between them. All used three percentages of humic acid significantly increased vegetative growth (plant height, stem diameter, the aerial part dry weight), root growth (root number and roots dry weight) and chemical composition (photosynthetic pigments, NPK%, total phenolic and total flavonoids contents) over control. Humic acid at 4% more was effective treatment. All used bio-and/or mineral NPK fertilization treatments significantly increased all studied characters over control. The best treatments were 100% NPK or 75% NPK plus Minia Azotein. It could be recommended to add humic acid at 4% in combination with 100% NPK or 75% NPK plus Minia Azotein to improve growth of Delonix regia

Time dependent viscoelastic rheological response of pure, modified and synthetic bituminous binders

Bitumen is a viscoelastic material that exhibits both elastic and viscous components of response and displays both a temperature and time dependent relationship between applied stresses and resultant strains. In addition, as bitumen is responsible for the viscoelastic behaviour of all bituminous materials, it plays a dominant role in defining many of the aspects of asphalt road performance, such as strength and stiffness, permanent deformation and cracking. Although conventional bituminous materials perform satisfactorily in most highway pavement applications, there are situations that require the modification of the binder to enhance the properties of existing asphalt material. The best known form of modification is by means of polymer modification, traditionally used to improve the temperature and time susceptibility of bitumen. Tyre rubber modification is another form using recycled crumb tyre rubber to alter the properties of conventional bitumen. In addition, alternative binders (synthetic polymeric binders as well as renewable, environmental-friendly bio-binders) have entered the bitumen market over the last few years due to concerns over the continued availability of bitumen from current crudes and refinery processes. This paper provides a detailed rheological assessment, under both temperature and time regimes, of a range of conventional, modified and alternative binders in terms of the materials dynamic (oscillatory) viscoelastic response. The rheological results show the improved viscoelastic properties of polymer- and rubber-modified binders in terms of increased complex shear modulus and elastic response, particularly at high temperatures and low frequencies. The synthetic binders were found to demonstrate complex rheological behaviour relative to that seen for conventional bituminous binders

Galaxy And Mass Assembly (GAMA): data release 4 and the z < 0.1 total and z < 0.08 morphological galaxy stellar mass functions

Galaxie

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Applications of guar gum and its derivatives in petroleum industry: A review

Green chemistry approach is growing rapidly and the replacement of petroleum derived materials with bio-based materials is greatly enhanced for environmental and health concerns. Polymers from renewable natural resources have attracted an increasing amount of attention over the last three decades, predominantly due to two main reasons: firstly environmental concerns, and secondly the realization that our petroleum resources are finite. Natural polymers are available in large quantities from different renewable sources, while synthetic polymers are produced from non-renewable petroleum resources. They include proteins and polysaccharides. Among the most important polysaccharides is Guar gum which has been extensively used in a wide range of applications due to its unique properties. The objective of this review is to focus the light on Guar Gum and its derivatives. The chemical structure, sources, chemical modification, physical properties (mechanical properties and thermal stability), and some potential industrial applications are reviewed and discussed. Keywords: Natural polymers, Guar gum, Chemical modification, Drilling fluids, Thickening agent

Long term complications after radical cystoprostatectomy with orthotopic diversion in male patients: Preliminary experience

Introduction: Radical cystectomy is the standard treatment for patients with invasive bladder cancer and for those with superficial bladder cancer who did not respond to conservative TUR and intravesical therapy. Many diversions are available after radical cystectomy; the most attractive for the patients is orthotopic diversion due to better quality of life associated with this diversion. Objective: To evaluate the long-term outcomes beyond 1 year, both functional and oncological, in male patients treated with radical cystectomy and orthotopic diversion for invasive bladder cancer. Patients and methods: This is a retrospective study done at Cairo university hospitals. A total of 44 male patients underwent radical cystectomy and orthotopic diversion (W-pouch) for invasive bladder cancer with minimum follow up 1 year. Assessment included; neobladder function, renal pattern and function, ureteroenteric anastomotic stricture or reflux, survival, recurrence, erectile function, urolithiasis, and urinary tract infection. The tools used to assess the complications during each visit included; history including voiding diary and IIEF questionnaire, examination including PR, laboratory investigations including urine analysis and kidney function tests, pH (acidosis) and bicarbonates and radiological investigation including ultrasound, chest X-ray, CT abdomen and pelvis. Results: The mean follow up was 88 months (range 12–138). Stones developed post-operatively in four patients (two of them were pouch stones and the other two were renal stones), incision hernia developed in two patients (4.5%), uretero enteric anastomotic stricture in two patients (4.5%), recurrent UTI was recorded in 10 cases (23%), uremia and dialysis in 9.2% of cases, metastasis was recorded as follows: local 2%, distant 11.5% and both 4.5% and the mortality rate was 19% (over all survival was 81%). Nocturnal incontinence 29.5% (13 patients), stress incontinence 9.5% (4 patients), urge incontinence 9.5% (4 patients), total incontinence 4.5% (23 patients); while the remaining 21 patients (47.5%) were continent day and night. Erectile dysfunction developed post-operatively in 35 cases (80.5%). Conclusion: Long term follow-up for patients with radical cystectomy and orthotopic diversion is associated with high complication rate. Long term follow up for those patients is needed to verify the causes of complications and how to prevent them

Synthesis of some novel non ionic surfactants based on tolyltriazole and evaluation their performance as corrosion inhibitors for carbon steel

Five new synthesized non ionic surfactants (I–V) were synthesized and characterized using FTIR and NMR spectroscopic methods. Performance of the synthesized compounds as corrosion inhibitors for X- 65 type carbon steel in oil wells formation water was investigated by various techniques such as weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). It was found that the percentage inhibition efficiency (η%) increases by increasing the inhibitor concentration until the critical micelle concentration (CMC) is reached. Also, the results showed enhancement in inhibition efficiencies with increasing both molecular size of the surfactant and the degree of ethoxylation. Potentiodynamic polarization curves indicated that the inhibitors under investigation act as mixed type. The data obtained from electrochemical impedance spectroscopy (EIS) were analyzed to model the corrosion inhibition process through equivalent circuit. Finally, the nature of the protective film formed on carbon steel surface was analyzed by SEM and EDX techniques

Transdifferentiation of human fibroblasts into skeletal muscle cells: Optimization and assembly into engineered tissue constructs through biological ligands

The development of robust skeletal muscle models has been challenging due to the partial recapitulation of human physiology and architecture. Reliable and innovative 3D skeletal muscle models recently described offer an alternative that more accurately captures the in vivo environment but require an abundant cell source. Direct reprogramming or transdifferentiation has been considered as an alternative. Recent reports have provided evidence for significant improvements in the efficiency of derivation of human skeletal myotubes from human fibroblasts. Herein we aimed at improving the transdifferentiation process of human fibroblasts (tHFs), in addition to the differentiation of murine skeletal myoblasts (C2C12), and the differentiation of primary human skeletal myoblasts (HSkM). Differentiating or transdifferentiating cells were exposed to single or combinations of biological ligands, including Follistatin, GDF8, FGF2, GDF11, GDF15, hGH, TMSB4X, BMP4, BMP7, IL6, and TNF-α. These were selected for their critical roles in myogenesis and regeneration. C2C12 and tHFs displayed significant differentiation deficits when exposed to FGF2, BMP4, BMP7, and TNF-α, while proliferation was significantly enhanced by FGF2. When exposed to combinations of ligands, we observed consistent deficit differentiation when TNF-α was included. Finally, our direct reprogramming technique allowed for the assembly of elongated, cross-striated, and aligned tHFs within tissue-engineered 3D skeletal muscle constructs. In conclusion, we describe an efficient system to transdifferentiate human fibroblasts into myogenic cells and a platform for the generation of tissue-engineered constructs. Future directions will involve the evaluation of the functional characteristics of these engineered tissues